Elon Musk is on record for saying that Tesla cars would drive themselves by the end of 2017, adding that it would mean full autonomy with a reliability greater than that of a human.
In my opinion, the reason why Apple and Google have pulled out is not that the technology does not work, but that it is not yet demonstrably sufficiently reliable, and that cheap sensors that make the technology both feasible and economic are not out yet.
Meanwhile the traditional car makers are content with a partnership with the likes of Mobileye just to exist in this space.
Personally I believe full car autonomy is feasible, safe and useful on highways, and has been for some time. I'm not sure about economic. The other use cases are not so clear cut.